The Research Process: Grey Literature

What Is Grey Literature?

Grey literature refers to information created by governments, academics, businesses, and organizations that is not published through traditional commercial publishers.

Because of this, grey literature can sometimes be harder to find through standard library searches or bookstores. It may also vary in format, audience, and level of review.

A commonly cited definition describes grey literature as materials that are “not readily available through normal book-selling channels” (Wood, 1982).

Tip: Grey literature can be especially useful when you are researching emerging topics or areas where limited scholarly research is available.

Examples of Grey Literature

Grey literature includes a wide range of materials, such as:

• Theses and dissertations
• Conference papers and proceedings
• Reports (white papers, working papers, internal documents)
• Government documents and policies
• Technical notes and specifications
• Datasets and statistics
• Patents and regulatory data
• Preprints and unpublished research
• Company reports and organizational information
• Social media or public communications

For a more comprehensive list, visit: Document Types in Grey Literature (GreyNet International)

Why Use Grey Literature?

The term “grey” reflects some uncertainty around how these materials are reviewed, shared, or distributed. Even so, grey literature can be highly valuable in your research.

Some key benefits include:

• Timeliness: Information may be available more quickly than in peer-reviewed publications, sometimes appearing 12–18 months earlier
• Current updates: Online reports and organizational content may be updated more frequently
• Depth of information: Some sources (like dissertations) may include detailed data not published elsewhere
• Broader perspectives: Reports and white papers can provide big-picture views of issues
• Reduced publication bias: Grey literature is more likely to include negative or null results

Tip: Because grey literature may not always go through peer review, it’s important to evaluate each source carefully for credibility and relevance.

Using Grey Literature Effectively

Grey literature can strengthen your research when used thoughtfully—especially alongside scholarly sources.

As you evaluate grey literature, consider:

• Who created the information and their expertise
• The purpose and intended audience
• Whether the information is current and well-supported
• How it fits with other sources you’ve found

Challenges of Using Grey Literature

While grey literature can be a valuable part of your research, it may sometimes be more difficult to find and evaluate than traditional sources. Understanding these challenges can help you approach your search more effectively.

As you work with grey literature, keep in mind:

• It may not be widely shared or easily accessible
• Some materials may not be available online, or links may change over time
• Older documents may not be archived or preserved
• Formats and citation details can vary between sources
• The volume of available material can feel overwhelming at first
• Items may not include standard identifiers like ISBNs or ISSNs
• Many sources are not peer-reviewed, so quality and reliability may vary

Evaluating Grey Literature

Because grey literature is not always peer-reviewed, it’s especially important to evaluate each source carefully before using it in your work.

You can use the following tools to help guide your evaluation:

• Evaluating Information Guide
• AACODS Checklist (a structured tool for assessing grey literature)

Pro tip: Asking questions about who created the information, why it was created, and how current it is can help you decide whether it’s appropriate for your research.